Means for closing elevator doors



c. K. WILSON 2,509,712

MEANS FOR CLOSING ELEVATOR DOORS May 30, 1950 Filed June 25, 1947 2Sheets-Sheet 1 I N V EN TOR. C/ieafer' fl. M I/JOH BY @WA- (9mATTORNEY-9 y 1950 c. K. WILSON MEANS FOR CLOSING ELEVATOR DQORS 2Sheets-Sheet 2 7 Filed June 25, 1947 Zia/Q5 INVENTOR. Chas/6r A. Vii/sonBY 0 1/004 1,

Patented May 30, 1950 UNITED STATES PATENT OFFICE Application June 2 5,

2 Claims.

This invention relates to means for closing elevator doors. Morespecifically, it relates to' means for automatically completing theclosing of a nearly closed freight elevator door when the elevatorstarting switch is closed.

In closing elevator doors, especially doors of freight elevators, it hasbeencustomary to sinploy an electric motor controlled by a manuallyclosed switch that automatically opens instantly when the manual closingpressure is released, so that the door can be stopped instantly ifdanger develops of injury to a person having a member the path of theclosing door. It customary, also, to provide such doors with aninterlock which prevents the elevator from starting unless the door iscompletely closed This interlock is required by building codes whichspecify the maximum gap which may be left in the door and still allowthe elevator to operate.

In some cases the operator releases pressure upon the door-closingswitch when the door is nearly closed. but still leaves a gap wider thanthat specified so that the interlock prevents operation of the motor.The present invention is of utility under such circumstances. Theinvention comprises an automatic door-closing device operated upon theclosing of the elevator starting switch which will complete closing of anearly closed door, permitting operation of the interlock for elevatorstarting, but which will not operate if the door is open to a degreedangerous for automatic closing.

One embodiment oi" the invention is illustrated in the accompanyingdrawings, forming a part of this specification, and in which Fig. 1 is adiagrammatic illustration of a wiring arrangement for the invention,with the door closed sufficiently to allow immediate starting of theelevator; Fig. 2 is a View of the door slightly open, so that theinvention will function before the elevator starts; Fig. 3 is a sectionon the line 33 of Fig. 2, and Fig. 4 is a section on the line 44 of Fig.1.

In the embodiment illustrated in the drawings, the door consists of thelower half in and upper half ll. Chains it from the upper half pass overpulleys l3 and are attached to rods I4 extending up from the lower half,thus counterbalancing the two halves for opening and closing movement.Such movement of the door halves may be produced by actuating a motor I5connected by a reduction gear, (not shown) to a lever l5 provided with apin ll movable horizontally in a slot it in the upper half.

Motor I5 is reversible, and is actuated in doorclosing direction whenswitch 19 is closed and 2 in door-opening direction when switch 20 isclosed. "Switch I9 is closed by energizing coil 2!, one end of which ispermanently connected through xvii-e2 2 to power line 23. The other endor the coil 2] is connected by line 24 through switch 25 to line 2 6running through switch 21 to line 28., which in turn is connected toline 29 by switch 30. Line '29 is connected by switch 31 to line 32which is abranch of line 24. Leading from fine 2 6 is aline 33 connectedby a branch 34 to power line '35. g h I Switch 2 5 is or the push buttontype which is automatically opened when closing pressure is removed. Itwill be seen that motor l5 will be actuated in closing directionwhenever switch 25 closed, and also when all of switches 21, 30 and 3Tare closed.

Switch 21 is connected to a retiring cam 35 which operates a lever 31for unlocking the door, when projected, and when withdrawn allows thelever to lock the door provided catch 38 can project beneath the lowerhalf of the door. The cam is normally projected, and is retired byenergizing a coil 39.

Switch 30 is normally closed, but is opened upon the energizing of coil40 one end of which is connected permanently by wire 4| to power line 23and the other end of which is connected through a switch 42 to powerline 35. Switch 42 is open as long as the door is unlocked, but isclosed when catch 38 moves to a position under the lower half of thedoor. Switch 311 is normally opened, but is closed when a cam 43 on thelower half of the door engages a lever 44 and closes the switch againstthe pressure of spring 45.

The elevator motor is energized in the up direction by closing switch 46and in the down direction by closing switch 41, provided switch 48,interposed in the power line to the starting relays, is closed. Closingeither of the starting switches completes the circuit through coil 39and retires cam 35. If the door is closed so that catch 38 can movebeneath and lock the door, switch 42 is closed, energizing coil 40,opening switch 38 and closing switch 48. The closing of switch 48energizes the relay for starting the elevator motor.

If the door is not closed sufficiently to be locked when switch 46 isclosed, catch 38 engages the door and prevents the closing of switch 42and this in turn prevents the closing of switch 48 and the starting ofthe elevator motor. However, if the parts are in the position in which.they are shown in Figs. 2 and 3, with astragal 49 on the upper halfclosing the gap between the halves so as to avoid danger of anyonehaving an arm, hand or fingers between the door halves, switch 30 willremain closed, switch 3| will be closed by engagement of members 43 and44, and when switch 27 is closed as a result of closing switch 46, motorIE will be energized in the door-closing direction. As soon as the dooris closed sufliciently to be locked, switch 42 is closed, energizingcoil 40, opening switch 30 and de-energizing motor l5 and simultaneouslyclosing switch 48 and starting the elevator motor.

If an attempt is made to start the elevator when the door is open toowidely for cam 43 to operate lever 44 and close switch 3|, the closingmotor is not energized, and the elevator cannot be started until thedoor is closed by manual closing of switch 25.

It will be readily understood that cam 43 is made short enough so thatthere is no automatic closing of the door when it is open too far forsafe automatic closing, but when so nearly closed that further automaticclosing is safe, actuation of the starting switch automaticallycompletes the closing necessary for locking, and so the slightlyincomplete initial closing is overcome with a minimum of delay and withno additional movement by the operator.

By this invention, the operation of freight elevators is simplified andexpedited without decreasing the safety of operation.

While but one door is shown, it will be readily understood that theautomatic means for completing the closing may be added to the interlockfor each door of the elevator shaft.

While only one arrangement has been illustrated and described, variouschanges may be made while retaining the essential features set forth inthe appended claims.

What I claim is:

1. In an elevator installation comprising a door, a motor for closingthe door, a manually operable switch for starting the door motor, anelevator motor, a starting switch for the elevator motor, and aninterlock preventing the starting of the elevator motor when the door isincompletely closed, means automatically energizing the door motor forcompleting the closing of the door when the starting switch for theelevator motor is actuated if, and only if, the door is nearly closed.

2. In an elevator installation comprising a door, a motor for closingthe door, a manually operable switch for starting the door motor, anelevator motor, a starting switch for the elevator motor, and aninterlock preventing the starting of the elevator motor when the door isincompletely closed, a circuit for energizing the door motor in theclosing direction by-passing said manually operable switch andcomprising a switch closed by the closing of the starting switch for theelevator motor, a switch open when the door is widely open andautomatically closed when the door is closed, so nearly that its closingmay be safely completed automatically, and a switch automatically openedby the operation of the interlock when the door is completely closed.

C. K. WILSON.

REFERENCES CITED Name Date Neuschotz Dec. 5, 1933 Number

